The skin employs a host of protective mechanisms to defend itself against the ravages of the environment. One of the most widely studied protective mechanisms is the system of free radical scavengers. Free radical scavengers help to protect the skin by neutralizing dangerous substances that can be generated by sun exposure and pollution. Two such protective substances - superoxide dismutase and peroxidase - were examined for their ability to reduce UV-induced erythema. The ability to reduce erythema is a measure of anti-irritant capabilities, which can also be thought of as free radical scavenging ability. There has been some research that shows that superoxide dismutase (SOD) and peroxidase work synergistically. The action of SOD, which neutralizes the superoxide anion, can sometimes produce hydrogen peroxide, which can have a detrimental effect on the lipid barriers of the skin. When peroxidase is present, it can work to neutralize the hydrogen peroxide, thus giving a full spectrum of free radical protection. The present study employs a superoxide dismutase extracted from yeast. The peroxidase is found in an aqueous extract of fennel (Foeniculum vulgare). Minimal erythemal dose (MED) was determined on the panellists. Test compounds were then applied and then they were exposed to solar simulators in doses equivalent to their respective MEDs. Development of erythema was then measured via chromameter, and reduction in the development of redness was determined.